loosing coolant through pressure

[williamson02]

loosing coolant out of reservior and only topping up radiator with about one cup of coolant car does not get hot but pressurizes and blows out coolant through over flow hose no water in oil when checking dip stick but there is a small amount of oil in radiator it is not brown or milky more grey than any thing could it be transmission fliud ?

[hako]

Welcome to the forum.
Is there any chance you are overfilling the reservoir? The oil in the radiator can be from a recent gasket change somewhere (some mechanics use grease to seal) or some radiator sealants contain soluble oil. Others use oil to help the hoses slip on so there are many different ways oil can get into the coolant. Check the radiator cap and see if there is any oily stuff on the seal....if the cap is worn replace it. Unless the car is showing other problems - white smoke or missing then I'd be inclined to drive it normally and keep an eye on it....Good Luck.

[williamson02]

have already changed radiator cap and not over filling reservoir also no new hoses or gaskets still driving ever day about 600 ks a week thanks for the reply